Sex Reversal After Exposure to Atrazine (image) University of Illinois at Urbana-Champaign Caption Both of these African clawed frogs are genetically male, but lifelong exposure to the herbicide atrazine transformed the frog on the bottom to female. The frog reproduced with normal males twice. Credit Tyrone Hayes Usage Restrictions Photo may be used only to accompany stories about the research described in this news release. Please credit: Tyrone Hayes. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.